Derrick



(No Model.)

T. GAPPNEY.

DERRIGK.

No. 308,486. Patented Nov. 25, 1884.

NITED STATES THOMAS GAFFNEY, OF DETROIT, MICHIGAN.

DERRICK.

SPECIFICATION forming part of Letters Patent No. 308,486, dated November 25, 1884-.

Application filed July 9, 1884.

To all whom t may concern.-

Be it known lthat I, THOMAS GAFFNEY, of Detroit, in the county of Vayue and State of Michigan, have invented new and useful Improvements in Derricks; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing, which forms a part of this specification.

This invention relates to certain new and useful improvements in the construction of builders7 derricks.

The invention consists in the peculiar construction and application of an adjustable jib and in the peculiar construction, arrangement, and various combinations of the parts, all as more fully hereinafter set forth.

In the accompanying drawing, which forms a part of this specification, my invention is shown in the figure in perspective, and in which- A represents the post, B the jib, and O the stay, of my improved device.

D is an extension-jib secured upon the top of the jib B in any convenient manner, and provided with a suitable locking device, a. The lower ends of the staybars are connected together by a girt, E, which is designed to rest upon a shoulder, b, of the post.

F is a windlass properly journaled in the stay, and is provided-with a crank-handle, e, by means of which it is operated. The rope or cable G passes from this windlass up to and over the pulley H at the end of the extensionjib D, and thence down to the article to be hoisted.

I and J represent guys by means of which the device is secured to position.

(No model.)

In practice this device is designed for the use of builders in elevating material to the roof to of a building, and it can readily be seen that it can easily be adjusted upon the roof, so that the load can be deposited at almost any point.

It will also be observed that the stay and jib swing upon the post, and that the eXtension-jib can readily be extended as the nature of the work to be done may require,y

What I claim yas my invention is- 1. In a derrick, the combination of the post A, having shoulder b, jib B, pivoted to the upper end of said post, and the stay-bars O, the upper ends of which are connected to the said jib and the lower ends joined by the girt E, leaving a space between said bars for the windlass F, which girt is adaptedl to rest on said shoulders b, substantially as and for the purposes specified.

2. The combination, with the vertical postA, j ib B, pivoted to the top thereof, and the sta-y O, of thejib D, supported by and adjustable on said jib B, substantially as and for the purposes set forth.

3. In a derrick, the combination of the post A, having vshoulder b, jib B, pivoted on the top of said post, the stay-bars O, the upper ends of which are secured to the jib B and their lower ends joined by the girt E, which rests on said shoulder, the windlass F, journaled in said stay-bars, and the jib D, supported by and adjustable on the jib B, sub- 7o stantiall y as described.

THOMAS GAFFNEY Witnesses:

H. S. SPRAGUE, CHARLES J. HUNT. 

